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Article
Publication date: 19 May 2021

Hua-Lin Yang, Xiulong Li, Weiwei Sun, Fang Deng and Jie Du

This paper aims to present the mixed elastohydrodynamic lubrication (EHL) model and obtain the leakage characteristics for the skeleton reciprocating oil seal.

Abstract

Purpose

This paper aims to present the mixed elastohydrodynamic lubrication (EHL) model and obtain the leakage characteristics for the skeleton reciprocating oil seal.

Design/methodology/approach

The model consists of a finite element analysis of the contact pressure, a fluid mechanics analysis of the fluid film, a contact analysis of the asperity contact pressure, a deformation analysis of the seal lip and an iterative numerical simulation process.

Findings

Simulation results show that the leakage is in direct proportion to the seal roughness and speed, and in inverse proportion to the fluid viscosity. Comparisons with the experimental results verify the validity of the mixed EHL model.

Originality/value

This study provides a helpful method to calculate the leakage of the skeleton reciprocating oil seal, which shortens its development cycles.

Details

Industrial Lubrication and Tribology, vol. 73 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 March 2021

Delei Zhu and Shaoxian Bai

The purpose of this paper is to acquire sealing properties of supercritical CO2 (S-CO2) T-groove seal under ultra-high-speed conditions by thermo-elastohydrodynamic…

Abstract

Purpose

The purpose of this paper is to acquire sealing properties of supercritical CO2 (S-CO2) T-groove seal under ultra-high-speed conditions by thermo-elastohydrodynamic lubrication (TEHL) analysis.

Design/methodology/approach

Considering the choked flow effect, the finite difference method is applied to solve the gas state equation, Reynolds equation and energy equation. The temperature, pressure and viscosity distributions of the lubricating film are analyzed, and sealing characteristics is also obtained.

Findings

The face distortions induced by increasing rotational speed leads to the convergent face seal gap. When the linear velocity of rotation exceeds 400 m/s, the maximum temperature difference of the sealing film is approximately 140 K, and the viscosity of CO2 is altered by 17.80%. Near the critical temperature point of CO2, while the seal temperature increases by 50 K, the opening force of the T-groove non-contact seal enhances by 20% and the leakage rate declines by 80%.

Originality/value

The TEHL characteristics of the T-groove non-contact seal are numerically analyzed under ultra-high-speed, considering the real gas effect and choked flow effect. In the supercritical conditions, the influence of rotational speed, seal temperature, seal pressure and film thickness on sealing performance and face distortions is analyzed.

Details

Industrial Lubrication and Tribology, vol. 73 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 19 November 2020

Yun-lei Wang, Jiu-hui Wu, Zhen-tao Li and Lu-shuai Xu

The purpose of this paper is to investigate the effect of slip position on the performance of liquid film seal.

Abstract

Purpose

The purpose of this paper is to investigate the effect of slip position on the performance of liquid film seal.

Design/methodology/approach

A mathematical model of liquid film seal with slip/no-slip surface was established based on the Navier slip model and JFO boundary condition. Liquid film governing equation was discretized by the finite difference method and solved by the SOR relaxation iterative algorithm and the effects of slip position on sealing performance are discussed.

Findings

The results indicate that boundary slip plays an important role in the overall performance of a seal and a reasonable arrangement of slip position can improve the steady-state performance of liquid film seal.

Originality/value

Based on the mathematical model, the optimal parameters for liquid film seal with boundary slip at groove are obtained. The results presented in this study are expected to provide a theoretical basis to improve the design method of liquid film seal.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0082/

Details

Industrial Lubrication and Tribology, vol. 73 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 18 September 2020

Fuying Zhang and Yuanhao Zhang

The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction…

Abstract

Purpose

The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of triangular texture on the sealing performance was further analyzed.

Design/methodology/approach

Based on the theory of elastohydrodynamic lubrication and the pumping mechanism of rotary shaft seals, establishing a numerical model of mixed lubrication in oil seal sealing area. The model is coupled with the lip surface texture parameters and the two-dimensional average Reynolds equation considering the surface roughness.

Findings

The results show that the application of lip surface texture technology has obvious influence on the oil film thickness, friction torque and pumping rate of oil seal. The triangular texture has the most significant effect on the increase of pump suction rate. When the rotation direction of triangular texture is 315 degrees, the pumping rate of oil seal is the largest compared with the other seven directions.

Originality/value

The model has a comprehensive theoretical guidance for the design of new oil seal products, which provides a certain basis for the application of surface texture technology in the field of sealing in the future.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0198/

Details

Industrial Lubrication and Tribology, vol. 73 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 11 September 2020

Delei Zhu and Shaoxian Bai

The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO2 (S-CO…

Abstract

Purpose

The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO2 (S-CO2) spiral groove face seals in the supercritical regime.

Design/methodology/approach

The spiral groove face seal was used as the research object. The distribution of lubricating film pressure and temperature was analysed by solving the gas state, Reynolds and energy equations using the finite difference method. Furthermore, the influence law of sealing performance was obtained.

Findings

Close to the critical temperature of S-CO2, face distortions produced by increasing pressure lead to divergent clearance and resulted in reduced opening force. In the state of S-CO2, the face distortions generated by increasing seal temperature lead to convergent clearance, which enhances the opening force. In addition, near the critical temperature of S-CO2, the opening force may be reduced by 10%, and the leakage rate of the seal sharply increases by a factor of four.

Originality/value

The thermoelastohydrodynamic characteristics of supercritical CO2 face seals are illustrated considering the actual gas effect including compressibility, heat capacity and viscosity. Face distortions and sealing performance were calculated under different seal pressures and seal temperatures in the supercritical regime, as well as with N2 for comparison.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0169/

Details

Industrial Lubrication and Tribology, vol. 73 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 5 March 2020

Fei Lu, Jian Liu and Hongyan Lu

The carbon/carbon (C/C) composite finger seal experiment was performed on a high-speed seal tester. The purpose of this paper is to investigate the leakage and wear…

Abstract

Purpose

The carbon/carbon (C/C) composite finger seal experiment was performed on a high-speed seal tester. The purpose of this paper is to investigate the leakage and wear characteristics of C/C composite finger seal under various operating conditions.

Design/methodology/approach

Static, dynamic, endurance and post endurance tests were carried out. For static and performance tests, the pressure differential changed from 0.1 to 0.6 MPa and the rotor speed varied from 1,000 to 9,000 r/min. Two endurance tests were conducted for 4 h, with each mounting two finger seals. The seal leakage was monitored by mass flowmeters, and the wear depth was measured and calculated by using three-dimensional profilometer.

Findings

Results showed that the seal leakage increases with pressure differential but decreases with rotor speed. Leakage rate is lower when speed is decelerated than that with the speed stepped up. During a time history, material removal caused by wear has significant influence on leakage data causing higher leakage than the results before endurance test. Particular interest is that the uneven wear characteristic on finger foot bottom was firstly revealed, showing severe wear in foot heel area than that in foot toe.

Originality/value

This study could provide experimental guidance for finger seal designers. Additionally, the uneven wear characteristic of finger foot was firstly revealed, which showed the necessity of further theoretical research on finger seal wear.

Details

Industrial Lubrication and Tribology, vol. 72 no. 10
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 19 September 2019

Jing Xie, Shaoxian Bai and Chunhong Ma

The purpose of this paper is to improve opening performance of bi-directional rotation gas face seals by investigating the hydrodynamic effect of non-closed elliptical grooves.

Abstract

Purpose

The purpose of this paper is to improve opening performance of bi-directional rotation gas face seals by investigating the hydrodynamic effect of non-closed elliptical grooves.

Design/methodology/approach

A model of non-closed elliptical groove bi-directional rotation gas face seal is developed. The distribution of lubricating film pressure is obtained by solving gas Reynolds equations with the finite difference method. The program iterates repeatedly until the convergence criterion on the opening force is satisfied, and the sealing performance is finally obtained.

Findings

Non-closed elliptical groove presents much stronger hydrodynamic effect than the closed groove because of drop of the gas resistance flowing into grooves. Besides, the non-closed elliptical groove presents significant hydrodynamic effect under bi-directional rotation conditions, and an increase of over 40 per cent is obtained for the opening force at seal pressure 4.5 MPa, as same level as the unidirectional spiral groove gas seal. In the case of bi-directional rotation, the value of the inclination angle is recommended to set as 90° presenting a structure symmetry so as to keep best opening performance for both positive and reverse rotation.

Originality/value

A model of non-closed elliptical groove bi-directional rotation gas face seal is established. The hydrodynamic mechanism of this gas seal is illustrated. Parametric investigation of inclination angle and integrity rate is presented for the non-closed elliptical groove bi-directional rotation gas face seal.

Details

Industrial Lubrication and Tribology, vol. 72 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 10 August 2015

Marcin Szczech and Wojciech Horak

The purpose of this publication is to determine the influence of selected factors on the durability and the tightness of ferrofluid seals working in water environments…

Abstract

Purpose

The purpose of this publication is to determine the influence of selected factors on the durability and the tightness of ferrofluid seals working in water environments. Ferromagnetic fluid (FF) seals are one of the most common applications of magnetic fluid. New applications can be developed by extending the capabilities of these seals in fluid environments, especially in water.

Design/methodology/approach

Tests were performed using ferrofluids with differing physical properties like density, dynamic viscosity and saturation magnetization. Working conditions, such as water pressure and peripheral speed, were taken into account.

Findings

A mathematical description which allows the selection of an appropriate ferrofluid and the determination of the operating parameters of an FF seal was developed.

Originality/value

This study concerns the influence of peripheral speed, water pressure and magnetic fluid properties on seal tightness.

Details

Industrial Lubrication and Tribology, vol. 67 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 June 2005

Wlodzimierz Ochonski

To present some new designs of magnetic fluid exclusion seals for rolling bearings and possibility to use them in modern industrial sealing applications.

Abstract

Purpose

To present some new designs of magnetic fluid exclusion seals for rolling bearings and possibility to use them in modern industrial sealing applications.

Design/methodology/approach

In the paper is given principle of magnetic fluid sealing technology and are presented new designs of magnetic fluid exclusion seals for rolling bearings, such as compact magnetic fluid seals, two‐stages seals being combination of magnetic fluid seal and labyrinth seal or radial lip seal, magnetic fluid seals with “floating” magnetic system. This paper also shows examples of their application in various rotating process equipment.

Findings

Provides information about new designs of bearing seals and gives the main advantages of these seals over other types, such as total tightness, low viscous drag, maintenance‐free service and high reliability.

Originality/value

This paper offers some new designs of high‐performance magnetic fluid exclusion seals for rolling bearings and points their practical applications.

Details

Industrial Lubrication and Tribology, vol. 57 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 August 2018

Han Qing, LiangXi Xie, Lu Li and Chuang Jia

This paper aims to establish a numerical model to calculate contact pressure for rectangular vane sealing surface of hydraulic rotary actuator. Numerical model can be…

Abstract

Purpose

This paper aims to establish a numerical model to calculate contact pressure for rectangular vane sealing surface of hydraulic rotary actuator. Numerical model can be applied to solve the steady-state Reynolds equation after the oil film thickness and the contact pressure distribution curve of the vane sealing surface are obtained.

Design/methodology/approach

The authors established the numerical model of contact pressure base on the theory of elastic after, the Reynolds equation is solved by the inverse solution.

Findings

The relationship between the oil film thickness of vane sealing surface and the contact pressure on different sealing location for hydraulic rotary actuator is obtained. At the same time, the lubrication state on the surface of seal is also found when the hydraulic rotary actuator runs stably.

Originality/value

The study shows that the lubricating state of the vane sealing surface is mixed lubrication, when the rotor of the hydraulic rotary actuator is running stably at a certain speed. Meanwhile, this research will provide a theory basis for later experiment for the hydraulic rotary vane actuator.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

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